<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
  <style>
    .green{
      color: green;
      background: red;
      text-align: center;
      line-height: 100px;
    }
    .big{
      width: 100px;
      height: 100px;
    }
  </style>
</head>
<body>
    <div id="app">
        <button @click="flag=!flag">click</button>
        <div class="green big" v-show="flag">高小乐</div>
    </div>
</body>
<script src="./js/vue.js"></script>
<script>
  new Vue({
    el:"#app",
    data:{
        flag:true
    }
  });
</script>
</html>